New Conjugated Polymer Based on Dihydroindoloindole for LEDs

New electroluminescence polymer, poly(5,10-dihexyl-5,10-dihydroindolo[3,2-b]indole-2,7-diyl) (PININO) was synthesized by Yamamoto conditions with Ni(0) catalyst. The full characterization of structures and properties as well as the performances of the electroluminescence devices of the new polymer are presented. The resulting polymer, which exhibits good solubility in common organic solvents, was used as the electroluminescence layer for the light-emitting diodes (LEDs) (ITO/PEDOT/polymer/Al). PININO shows turn-on voltage of 2.5 V, and electroluminescence (EL) with maximum peak at 490 nm, maximum brightness of 40 cd/ m² at 8 V, and efficiency of 0.002 cd/A at 350 mA/ cm² .